Transcriptome analysis of the denitrifying cells of Haloferax volcanii.

Haloferax volcanii is a facultative anaerobe and can grow by denitrification or by dimethyl sulfoxide (DMSO) respiration under anaerobic condition. Induction of denitrification and DMSO respiration in H. volcanii has been shown to be positively regulated by haloarchaea-specific DNA-binding protein NarO and by its homologous protein DmsR, respectively. Anaerobic growth of H. volcanii by DMSO respiration was inhibited by nitrate, but the denitrifying growth was not influenced by an addition of DMSO. Comparative transcriptome analysis between the denitrifying and the aerobic cells of H. volcanii revealed that the fluctuation of the extensive gene expression involving activation of denitrifying genes and suppression of the DMSO reductase gene under denitrifying condition. Reporter assay experiment suggested that DMSO respiration is under nitrate-dependent negative regulation by NarO.